In certain conventional network systems, application firewalls are used to screen web content for potential security risks before passing the web content to a client, server or other networked device. As an example, a client on a network may request a web page hosted by a remote server. The client's server may relay the request to the remote server, and receive from the remote server an HTTP response representative of the requested page. An application firewall in operation at the client's server may process the HTTP response to determine whether it contains or lacks data which might be indicative of a security risk to the client. If the application firewall determines there is no security risk associate with the HTTP response, the client's server may cache the page and transmit it to the client.